Timeline of Key Milestones

Volkswagen, Audi, and Porsche installed software on certain diesel vehicles that is designed to detect when the vehicle is undergoing emissions testing and turns full emissions controls on only during the test. The effectiveness of emissions control devices is reduced during all normal driving. This results in cars that meet emissions standards in the laboratory or testing station, but during normal operation, emit nitrogen oxides at levels up to 40 times the standard. This software is a "defeat device" that is prohibited under the Clean Air Act.

On September 18, 2015 EPA issued a Notice of Violation of the Clean Air Act to Volkswagen AG, Audi AG, and Volkswagen Group of America, Inc (collectively, “Volkswagen”). The notice alleges that Volkswagen installed software in its model year 2009-2015 2.0 liter diesel cars that circumvents EPA emissions standards. These vehicles emit up to 40 times more pollution than emissions standards allow.

On September 25, 2015, EPA announced that defeat device screening protocols would be included in compliance oversight programs going forward.

On November 2, 2015 EPA issued a different Notice of Violation of the Clean Air Act to Volkswagen, Audi, and Porsche for producing and selling certain model year 2014-2016 3.0 liter diesel cars and SUVs that include a software device that circumvents EPA emissions standards for certain air pollutants. These vehicles emit up to nine times more pollution than emissions standards allow. Subsequently, on November 19, 2015, Volkswagen officials informed EPA that the defeat device has existed in all of its U.S. 3.0 liter diesel models since 2009.

On January 4, 2016, the Department of Justice filed a complaint on behalf of EPA against Volkswagen AG, Audi AG, Volkswagen Group of America, Inc., Volkswagen Group of America Chattanooga Operations, LLC, Porsche AG, and Porsche Cars North America, Inc. for alleged violations of the Clean Air Act.​

On June 28, 2016 Volkswagen entered into a multi-billion dollar settlement to partially resolve alleged Clean Air Act violations based on the sale of 2.0 liter diesel engines that were equipped with software designed to cheat on federal emissions tests, known as “defeat devices.” The settlement was formally entered and took effect on October 25, 2016.

On December 20, 2016, Volkswagen entered into a second settlement to partially resolve alleged Clean Air Action violations based on the sale of 3.0 liter diesel engines that were equipped with software “defeat devices” designed to cheat on federal emissions tests which are in violation of the Clean Air Act and California law.

Coordination with California

EPA is working closely with our partner California's Air Resources Board to address the Volkswagen violations.

In addition, EPA and its partners the California Air Resources Board and Environment Canada are testing all current 2015-2016 light duty diesel vehicles to screen for potential defeat devices. The agencies will announce the results when testing is complete.